Model Boat Mayhem

Technical, Techniques, Hints, and Tips => BRUSHLESS Motors and Speed Controllers => Topic started by: AlanP on February 17, 2013, 04:49:06 pm

Title: repairing brushless motor
Post by: AlanP on February 17, 2013, 04:49:06 pm
The motor in question is 3650  x 3600kv 60amp, don't know the make. After a good run this morning the motor was taken out to remove the flex for greasing (best way for me) on turning the motor by hand it felt quite rough, so I dribbled a drop of oil into the bearings, this made no difference, so I am thinking there is something inside or the magnets have come loose, so my question is how do I get the end cap off as there are no screws holding it in place, your thoughts would be welcome.  :-))
 
Alan
Title: Re: repairing brushless motor
Post by: grasshopper on February 17, 2013, 04:55:22 pm
When you say 'rough' you don't mean ' coggy' at all?


Some motors feel rough but it's the rare earth magnets reacting to the coils making it feel less smooth than you might expect.
Title: Re: repairing brushless motor
Post by: AlanP on February 17, 2013, 05:00:17 pm
Hi grasshopper, I know the feeling of the magnets, this feels as though something is catching inside, thanks for the quick response
Alan
Title: Re: repairing brushless motor
Post by: grasshopper on February 17, 2013, 05:15:31 pm
Some decent photo's may be in order then before anyone could suggest  the method of dismantling.
Title: Re: repairing brushless motor
Post by: AlanP on February 17, 2013, 06:29:44 pm
here you go
Title: Re: repairing brushless motor
Post by: AlanP on February 17, 2013, 06:30:55 pm
and again
Title: Re: repairing brushless motor
Post by: AlanP on February 17, 2013, 06:31:40 pm
last one
Title: Re: repairing brushless motor
Post by: grasshopper on February 17, 2013, 06:36:10 pm
Not sure about yours, but I have seen motors where the black disc at the cable end is a cover and the screws are underneath.

Title: Re: repairing brushless motor
Post by: AlanP on February 20, 2013, 12:46:23 pm
Doesn't look like the rear disc comes off, so I think I will have a go at prising the front disc off  O0
Alan
Title: Re: repairing brushless motor
Post by: john44 on February 20, 2013, 06:50:42 pm
looks like the end caps are a press fit.

john
Title: Re: repairing brushless motor
Post by: AlanP on February 20, 2013, 08:59:05 pm
Correct John, and looks like a bit of super glue or something. A sharp tap with a small hammer (2lb)  :} on the output shaft and out it came, along with the four small black bits, I cant see where these have come from though, so it will be put back together without the small black bits and tried, if it seems ok ill put it back in the boat and test it, probably to distruction  <:(
For those that are interested, the boat is a Rocket, motor 3600kv run on 11.1v with a 35mm prop, reckon it was doing about 35mph till the motor became sick.
Alan
 
Title: Re: repairing brushless motor
Post by: Mad_Mike on February 20, 2013, 09:09:40 pm
Rather you than me i must say. I wouldnt have been able to watch me take 2lb hammer to a motor like that. Have the bits come off one of the end caps on the inside of the casing? do you they peice togeather into a circle or something?
Title: Re: repairing brushless motor
Post by: john44 on February 20, 2013, 09:26:54 pm
Put it on flebay as a brushless motor kit {-) {-) {-) {-)

only joking

john
Title: Re: repairing brushless motor
Post by: malcolmfrary on February 20, 2013, 10:21:55 pm
I am no expert in brushless motors, only looking in here to learn, but going off basic principals-
The motor consists basically of a case that has magnets glued to its insides which will hopefully be held in close proximity to the magnet on a stick which in turn will be kept in place by the bearings at the ends of said can. 
The stray black bits. logically, came from somewhere, peering down the hole might reveal just where.  When they separated from their proper place, they were probably the source of the original noise.  They COULD have been holding something in place, whatever void they left might need filling with, if nothing better is suggested, a bit of epoxy.
Title: Re: repairing brushless motor
Post by: AlanP on February 20, 2013, 11:32:16 pm
Well yes they did come from somewhere, on the inside of the can are the windings, these seem intact, with no apparent holes, although the black bits are a bit mangled, close inspection seems to indicate that they seem to have come from the shaft (hole in center when put together) they are not a spacer as there is no play fore and aft.
If you look at the rotor there is a metal piece at each end, one of these has a very small gap between it and the magnet, wondering if it has come from there. Out with the two mix and make sure that the rescue boat is in working order  :}
Title: Re: repairing brushless motor
Post by: EDWOOD on February 24, 2013, 03:55:27 pm
hi al dont think it will work now after todays little escapade oh what a mess when two rockets collide all the joys of fast electrics
all the best Ted
Title: Re: repairing brushless motor
Post by: AlanP on February 24, 2013, 04:16:35 pm
Oh yes it will, just tried it on another boat  :-))  but my best ESC is sick <:(
 
Alan